Typewriting machine



July 29, 1941. w, DQBSQN 2,251,122

TYPEWRITING MACHINE 7 Filed Oct; 26, 1939 2 Sheets-Sheet l ATTORNEY July 29, 1941. w. A; DOBSON .TYPEWRIT ING MACHINE Filed Oct. '26, 1959 2' Sheets-Sheet 2 INVENTOR MAL/14M A. 00550 Patented July 29,1941

ATENT orrlca TYPEWRITING MACHINE William A. Dotson, Wetliersfield, Conn, assignor to Underwood Elliott Fisher Company, New York, N. Y. a corporation of Delaware Application center as, 1939, Serial No. 301,443

rugged and reliablyoperative construction, ca-

such as the carriage drive means, the letter feed mechanism, margin stop mechanism parts, and the line-end signal, as well as the wing scale and the ribbon carrier associated therewith.

.In its more specific aspect, the invention provides platen carriage mounting-means comprising an elongate solidbar having an upper in clined face upon which the lower carriage rail is secured, the bar providing support and reinf forcement for the rail which is preferably formed of light-weight sheet-metal. This supporting bar, being of massive form having ends of appreciable area, is adapted .to have plate-like caseshift arms secured to its ends, these arms having pivot pins thereon journaled in'bearing plates secured to the main frame, and forming a simple case-shiftable mount for the carriage. The transverse bar, being adapted for manufacture as by die casting, also afiords an economic mounting on the various faces for'the sundry devices and mechanisms associated with the carriage. The case-shift carriage mechanism constructed in accordance with the invention has the advantages of simple and economic construc* tion and assures that the various associated devices and mechanisms be maintained in accurate relation with the platen and its carriage; also afiording further advantages in the assembly and maintenance of the machine. e

Other objects and advantages will hereinafter appear.

In the drawings:

Figure 1 is a plan view of. the typewriter el n-j 5 bodying the invention, illustrating only the typewriter mechanisms and structure closely relating to the invention; the platen carriage and upper rail being.removed and other parts broken away to facilitate illustration.

Figure 2 is a transverse sectional view through the typewriter as shown in Figure 1, the view being taken on a 1ine-22 of Figure 1 showing the case-shift mechanism in normal and caseshifted positions. 4 Figure 3 is a fragmentary sectional view taken on line 3-3 of Figure 1.

Figure 4 is a fragmentary transverse sectional view taken on line 4-6 of Figure 1, and

Figure 5 is a perspective view of the bar embodying the mount for the platen carriage and associated devices, removed from the machine.

The typewriter embodying the invention includes the usual platen carriage l slidably mounted on carriage'rails 8, 9 and cooperating rollers It, to guide the platen in line-typing movement under influence of a carriage drive springacting on a drum H which tensions a band l2 attached .at its free end to an arm I3 on the carriage i, all in the well-known manner. The movement of the carriage in line-typing is controlled by the usual letter-feed escapement mechanism M having a pinion l5 cooperating with a rack I 6 on the carriage. The typing margins are determined in the usual manner by margin stops ll adjustably carried on a rack bar it and cooperating with a fixed counter-stop 20, see Figure 4; one of the margin stops also cooperating with a line-endsignal including a striker 2i and bell 22.

A wing scale 23 is provided atthe front of the platen, the scale being carried on a bar on which an arm 24 of a ribbon carrier 25 is pivotaily mounted at 26. The ribbon carrier.'25 is vibrated concomitantly with the actuation of the letter-feed mechanism It through a link 21 extending between a bell crank 28, arranged to actuate the said mechanism, and a pendent arm 29 on the ribbon carrier. The bell crank 28 is operatively connected to a dog rocker'3ll of the letter feed mechanism by a link, not shown. A link 3| connects the bell crank 28 with a universal bar, not shown, actuatable by any of the type actions, in the usual manner.

Back spacing of the carriage is effected by reciprocation of a slide arm 33 carrying a dog 34 adapted to cooperate with-the escapement wheel of theletter-feed mechanism it, the slide arm 33 being actuated from the usual back-spacer key on the keyboard which is operatively connected.

to the slide arm 33 by a link 35 and bell crank 36 pivoted on a bracket 3'! fixed on the machine.

In accordance with the invention, a massive elongate bar 38, adapted to be manufactured as by die casting, is arranged transversely of the machine beneath the lower carriage rail 9, the bar 38 having a plurality of angularly related faces including an inclined face 39' on which the rail 9 is secured as by screws 40 threaded into the bar. For compactness and to afford certain operating advantages, the carriage rails 8 and 9 are inclined at a substantial angle, as more clearly shown in Figure 2, and the bar face 39 iscorrespondingly inclined to receive the carriage rail 9.

A rear face 4! -of the bar 38 is substantially vertical in the normal position of the bar and is thus adapted to provide mounting for the carriage actuating spring drum II, the margin defining counterstop 20, and the line-end signal comprising the striker 2| and bell 22. The spring drum II has a stud 42 mounting same, this stud being threadedly engaged in the bar 38. The counterstop 20 includes lugs 43 which lie against the face 4| of the bar and are secured thereto by screws 44. The bell 22 has a mounting stud, not shown, passing therethrough and threadedly engaged in the bar 38; a bracket member of the striker 2| being clamped between the bell and the face-4| of the bar. The lineend signal as herein shown forms the subject matter of my co-pending application Serial No. 281,820, filed June 29,1939.

To provide a mounting for the letter-feed mechanism I4, the bar 38 has a boss 45 projecting downwardly therefrom, as more clearly shown in Figure 4, to the bottom face of which is secured a mounting plate 46 on which the operating parts of the letter-feed mechanism are carried.

The wing scale bar 23 has a bracket arm 41 integral therewith, which projects rearwardly beneath the platen as shown in Figure 4 for support on the bar 38. The rear end of the bracket arm 41 forms a mounting plate 48 .which is preferably secured to the underside of the lower carriage rail 9 by screws 49 passing through the rail and threaded into the plate 48; the bar 38 being recessed at this region to admit the plate, see Figure 1. Y

The supporting bar 38, being of solid massive form, provides at each end a flat face of substantial area, on each of which end faces is secured a plate-like arm 58 forming part of the case shift mechanism, each arm 50 including an end portion 5| having apertures receiving screws 52 engaged in threaded holes in the bar 38 to hold the arm 58 securely on the bar. Each arm 58 has a pivot pin 53 projecting outwardly therefrom and journaled in a plate 54 adjustably carried on each of the side members of the main frame. The manner of mounting the plates 54, as shown in Figure 3, is substantially similar to that shown and described in my application Serial No. 124,541, filed February 8, 1937 now Patent No. 2,178,682, issued November 7., 1939. The plates 54 are each made adjustable in order to vary the position of the platen to or from the printing point of the typewriter. Accordingly, each plate has parallel side edges engaging guide members 55, 56, and the plate is held in adjusted position .by clamp screws 51 extending through elongate slots in the main frame and threaded into the plate 54.

Each of the arms 50 includes an inwardly projecting flange from which extends downwardly a stop lug 6|, the members 68, 6| being preferably integral with the arm 50 and formed by bending portions thereof as shown. The stop lug 6| determines the upper and lower case-shift positions of the platen by engaging with adjustable stop screws 62 threadedly carried on cars 63 extending from each of the plates 54.

Eacharm 5|] extends forwardly of the bar 38 and has its forward end bent laterally to provide an apertured lug 64 through which the rear ends of case-shift levers 65, 66 project. Each case-shift lever 65, 66 is fulcrumed on a fixed transverse bar 61 on which certain elements of the type action system, not shown, may be pivoted. Each lever 65, 66 has adjacent its keycarrying forward end a resilient tongue 68 adapted to engage a button 68 of cushioning material secured preferably to the bottom member 10 of the typewriter mask to quietly arrest the case-shift lever in depressed position. The right-hand case shift lever 66 may be operated to lock in depressed position and thus serve as a case-shift lock, this lever being adapted to be sprung laterally while being depressed, by a wedging action in engagement with an inclined face H of a lug l2, and to be latched under said lug when fully depressed to hold the platen in upper case position. Release of the case-shift lock lever 66 may be readily effected by urging the key thereof laterally so as to sufficiently spring the lever to disengage lug l2 and thereafter permit the lever key to rise to normal position.

It will thus be seen that as the key of either case-shift lever 65 or 66 is depressed, the lever swings about its pivotpn bar 61 to rais the rear end of the lever whichfbeing disposed within the apertured lug 64 of the corresponding arm 50, swings this arm, the bar 38 and the entire platen carriage, about the axis of the pivots 53 to move the platen to upper case position as defined by the stop lug 6| engaging one of the stop screws 62, as shown in the dot-and-dash outline in Figure 2. As the case-shiftmechanism parts ap-- proach the upper case posiiton, the resilient tongue 68 comes into engagement with the button 69 to quietly arrest the mechanism, the tongue 68 yielding slightly so that the lug 6| comes into firm engagement with the stop screw.

Means are provided to releasably lock the mechanism in normal lower case position, the same being automatically released incident to the manual actuation of either case shift lever 65 or 66. On either one of the arms 50, herein the leftward arm, a forwardly projecting finger I5 is provided, the free end of this finger being bent laterally to form a lock lug 16. A cross shaft 11 is disposed to extend transversely of the machine and is pivoted on the side members of the main frame. At the end adjacent the stop lug 16, the shaft 11 has fixed thereon a hook arm 18 projecting upwardly from the shaft and having a hook-like end 19 adapted to hook over the upper edge of the lock lug 16. The rear end of the caseshift lever 65, extending through the apertured lug 64, engages the front edge of the hook arm 18, as shown in Figure 2. As the lever 65 is actuated, the rear end thereof swings upwardly and rearwardly and so coacts with the hook arm 18 as to wedge same rearwardly and thus cause the hook end to disengage the lock lug 16. An arm 88, which may be similar to the hook arm 18. is fixed on the cross shaft 11 adjacent the case-shift lever 66 at the other side of the ma- ,What is claimed is:

chine. Itwill be seen that the corresponding arm ill does not include a stop in: such as It in that a single locking hook is considered ample in view of the manner of mounting the caseeshiftable platen carriage. However. for economy in manufacture. the arm 80 maybe identical in form to the hook arm 18. The forward edge of the arm 80 has the rear end of the correspondin oaserear end of each lever 65, 88 has an initial idle movement in the aperture of the associated lug 6 6 before the lever 60 is moved, this initial movement of the lever being ample to first release the locking mechanism before the platen is actuated in case shifting. As; the depressed case-shift lever is released from upper case position, the

parts assume their normal lowercase position during which the hook arm it, under the 112- fiuence of the spring at, latches over the lock lug l6. After the platen carriage and arms come to rest in lower case position, the case shift lever 65 or 66 continues to swing under influence of its restoring spring 62 until the rear end of the lever rests against the lower end of the aperture in lug 6d. f

' The case shift mechanism constructed in accordance with the invention presents a number of features advantageous in the construction'and operation of the machine. The bar 38 may be economically formed as by die casting and thus a single operation produces this element in a light-weight ,metal in such form as to aflord adequate support and reenforcement for the sheet metal carriage rail, and an adequate eco- I extending forwardly from said bar and being articulated to thearm of the corresponding casea 1. Ina platen case-shift mechanism for typewriting machines having a main frame, a platen carriage, and a trackway including rails mounting said carriage for line typing movement; a

,massive elongate bar underlying and reinforcing one of said rails, said bar presenting end faces,

means for mounting and actuating said bar for pivotal case-shift movement of the platen carriage on the main frame, including plate-like arms each secured flatwise to an end face of said bar and having a pivot pin journaled in the main frame, and-manually operable case-shift levers each pivoted intermediate its ends on the main frame and each having an arm projecting rearwardly from its pivot, said' plate-like arms each shift lever.

2. Inc. platen case-shift mechanism for typewriting machines having a main frame, a platen carriage, and a trackway including rails mounting said carriage for line typing movement: a massive elongate bar underlying and reinforcing one of said rails, said bar presenting end faces, means for mounting and actuating said her forpivotal case-shift movement of the platen carriage on the main frame, including plate-like arms each secured flatwise to an end face of said bar and having a pivot pin journaled in the main frame, stop meanson the main frame limiting case-shift'movement of the platen carriage toupper and lower case positions, said plate-like arms each including a bent-oil lug cooperative with said stop means, and case-shift levers each pivoted intermediate its ends on the main frame and veach having an arm projecting nomical support for the sundry devices associated the transmission of sound-producing vibrations. Further, the bar 38"affords ahighly desirable means for attaching the case-shift arms 50 thereto, which arms consequently maybe constructed in simple, plate-like form, easily fabricated. With thearms 50 secured as shown to the and faces of the bar 39, the relatively light, thin arms are arranged to withstand the bending stress,

this stress being imparted in the direction of.

greater cross section. The advantages of economic construction and quiet dependable operarearwardly from its pivot, said plate-like arms each extending forwardly from said bar and being articulated to the arm of the corresponding case-shiftlever.

3. In a platen case-shift mechanism for typewrlting machines having a main frame, aplaten carriage, and a trackway including rails mounting said carriage for line typing movement: a massive elongate bar underlying and reinforcing one of said rails, said bar presenting end faces,

each pivoted intermediate its ends on the main frame and each havingan arm projecting rear- .wardly from its pivot, said plate-like arms each extending forwardly from said bar adjacent and parallel with the arm of the corresponding caseshift lever and-each including an apertured memberv at its forward end, said case-shift lever arm passing through the aperture of said member.

ticn afforded by the shift-actuating mechanism including the case-shift'levers 65, 66 and arms 50, the case-shift lock and the lower case locking means, are readily apparent. The parts are all of simple, light-weight construction and, in the organization shown, embody a reliably operative mechanism.

It will be understood that the invention herein specifically described, is shown in one embodiment for the purposes of illustration, and that the invention may be modified and embodied in varlous'other forms without departing from the spirit or scope of the invention as defined in the appended claims,

c. In a platen case-shift mechanism fortypewriting machineshaving a main frame, a platen carriage, and a trackway including rails mounting said carriage for line typing movement: -'a massive elongate bar underlying and reinforcing one of said rails, said bar presenting end faces.

* means for mounting and actuating said bar for pivotal case-shift movement of the platen carriage on the main frame, including plate-like frame and each having an arm projecting rear wardly from its pivot, said plate-like arms each extending forwardly from said bar adjacent the arm of the corresponding case-shift. lever and each including a bent-off portion at its forward end defining an aperture, 2. rock shaft Journaled in the main frame, and hook arms secured on said rock shaft, at least one of said hook arms normally engaging the corresponding plate-like arm to lock the carriage against case-shift movement, each hook arm being in alignment 10 

